2002 Toyota Tundra - Parking Lights Stay On After Key Off Engine Off – Work Around

First off, this is not a solution to the issue, it is a work around….

My 2002 Toyota Tundra developed an electrical gremlin last Spring. The
issue at hand is every once in awhile, the parking lights (marker lights) will
stay on, even after the light switch is set to off and the engine is off, key
removed from ignition. I could eventually get the lights to turn off by fiddle f’ing
around with the vehicle.

I checked J3 and J13 grounds, they look good and check out fine with an ohm meter
all the way back to the big daddy ground (EA) in the engine bay.

I have provided a scan of the Haynes manual page 12-39 so you can see the circuitry, parts
and the fuse involved with the parking lights.

The two most likely suspects are 1) Light Control Switch (combination switch) and 2) The
Integration relay. Both of these items I have no intention of replacing. Thus my work around.

The work around, in one sentence: Use a relay to remove and restore 12vdc to pin 6 of the Integration Relay.

If you look at the scan, you will see the 15amp TAIL fuse (drivers side fuse panel) feeding
pin 6 of the Integration Relay. This fuse you will remove and you will control the 12vdc at
this point.

Parts Used:

Automotive Relay – Part Number Dorman 84601

Specialized ECU Repair Car Fuse Holder Connector - Mini ATM

Add-a-circuit mini ATM


Refer to the backside of the drivers side fuse panel cover for fuse descriptions:

I used 15amp ACC for the Keyed 12vdc (to energize the relay).

I used the 15amp TAIL fuse location to incorporate the relay wiring.

The Relay wiring: Pin 85 > Switched 12vdc (15amp ACC). Pin 86 > Ground J3 or custom.
Pin 87 and Pin 30 go to 15amp TAIL fuse location.

I hope this helps someone down the line, I did quite a bit of searching on the webs for answers
to this issue, but there was never a solution posted or even a work around like this one.

If someone offers up a real solution that does not require spending money on the light switch or Integration Relay, I would be happy to check it out.
The nice thing about this work around, is there
is no splicing and to return to stock, you would just pull out the Dorman
relay and the add-a-circuit and put the original fuses back in. No fuss, no muss.

Pictures for your reference included.

 

Great write up. As someone who is all about work-arounds and "safely" McGivering things, this is right down my alley.
I like it.

Not to mention the money saved. That Integration Relay is not cheap.

 

Interesting work around. Is it all the parking lights including the dash lights? Or just the tail lights that stay on? Electrical gremlins are often due to corrosion. Had a vehicle that had weird cruise control, turn signal - brake interactions and it turned out to be corrosion in the bulb sockets themselves causing a short.

 

I need a little more information to pull this off. It's not clear to me where the add-a-circuit or the ECU repair lines go from the fuse block. It's probably obvious to most of you but I just see them dissappear behind the panel. Do they attach to the relay? If not, where does the relay go? Thanks

 

The red wires shown in the pics connect to the relay. A fourth wire is not shown in pics, it's a ground wire.

"The Relay wiring: Pin 85 > Switched 12vdc (15amp ACC). Pin 86 > Ground J3 or custom.
Pin 87 and Pin 30 go to 15amp TAIL fuse location."

 

Much appreciated! Pretty much exactly what you'd already said I see. Thanks for being patient.